May 9, 2024

CDC Publishes Updated Guidance for Worker Protection from Novel Influenza A Viruses

Updated interim recommendations published recently by CDC outline steps workers and employers should take to reduce exposure to novel influenza A viruses associated with disease in humans. The agency’s updated guidance identifies occupational groups that may be at increased risk of exposure to these viruses: poultry and livestock farmers and workers, backyard bird flock owners, veterinarians and veterinary staff, animal health responders, public health responders, and slaughterhouse workers who handle lactating dairy cattle. CDC urges these workers to avoid unprotected direct or close physical contact with sick birds, livestock, or other animals; carcasses of animals that have died from unknown causes; raw milk; viscera, or internal organs, and udders from lactating dairy cattle; feces or litter; and surfaces and water that might be contaminated with waste from potentially infected animals.

CDC’s interim recommendations are related to the confirmed highly pathogenic avian influenza A(H5N1) infection of a dairy worker in Texas who worked with presumably infected cows in late March. The infection marked the first instance of cow-to-human spread of HPAI A(H5N1) virus and the second confirmed infection of a human. News articles from recent weeks describe how researchers were unable to conduct a follow-up investigation of other exposures among workers at the dairy farm where the infected person worked, and how some experts are concerned that cases of H5N1 among dairy workers are being missed.

CDC recommends the following personal protective equipment to protect workers against novel influenza A viruses: fluid-resistant coveralls, NIOSH-approved particulate respirators rated N95 or higher, properly fitted unvented or indirectly vented safety goggles, rubber boots or rubber boot covers, head or hair covers, and gloves. If there is a risk of liquid splashing onto a worker’s respirator, the agency recommends the use of a face shield. A waterproof apron may also be worn depending on the tasks to be performed. Steps for safely donning and doffing PPE and information about what workers should do after moving PPE are also covered in CDC’s recommendations.

CDC characterizes the current public health risk of H5N1 avian flu as low. However, the team of researchers that investigated the confirmed infection of the dairy worker caution that “[v]igilance is needed because if HPAI A(H5N1) virus adapts and becomes established among cows or other mammals, the risk to public health may increase.” The team’s letter about their findings was published last week in the New England Journal of Medicine.

CDC’s interim recommendations are available from its website. The agency also has information specifically for veterinarians who may evaluate and handle cats that have been exposed to HPAI A(H5N1).